Gimbal mounting



Aug. 9, 1955 Filed July 31, 1953 E. A. ZElTLlN GIMBAL MOUNTING 2Sheets-Sheet l INVENTOR.

ELI A. ZEITLIN ATTORNEYS Aug. 9, 1955 Filed July 51, 1953 2 Sheets-Sheet2 I8 Q I ll. Q 20 J 2; I INVENTOR.

ELI A. ZEITLIN L 35 ll A 36 38 x\\\\\\\\x\\\\\\vl- -1s\\\\ Inn 40 a IATTORNEYS United States Patent Ofiice fi,'il5,ilb7 Patented Aug. 9, 1955GIMBAL MOUNTING Eli A. Zeitlin, China Lake, Calif.

Application July 31, 1953, Serial No. 371,740

13 Claims. (Cl. 248-180) (Granted under Title 35, U. S. Code (1952),see. 266) The invention described herein may be manufactured and used byor for the Government of the United States of America for governmentalpurposes without the payment of any royalties thereon or therefore.

This invention relates to gimbal mountings or sup ports, and isparticularly concerned with novel structure providing a gimbal supportsystem which allows free movement of a reaction means about any of threemutually perpendicular axes.

Gimbal support structures, especially for use in three dimensionalflight simulation tables, are well known. The

main criteria for gimbal support systems employed for the aforementionedpurpose are rigidity of the structure and resistance to deflection andbending of the structural elements of the device during its operation,in order to obtain accurate readings from the instruments placed on thetable.

Gimbal systems utilized in flight simulation tables in the past have,for example, employed dome structures supported and rotated by largesector gears, or a single yoke supported on a vertical shaft forrotation thereby.

However, the prior art structures have not proven suificiently rigid andresistant to deflection in operation to obtain satisfactory results,generally in the form of readings taken from instruments placed on thetable. Thus, in the case of the above noted structure utilizing thelarge sector gears, the latter permit undesirable deflection and at thesame time are difficult to manufacture accurately, while in regard tothe devices employing the yoke structure, comparatively largedeflections are produced in the elements comprising the yoke and in thevertical shaft serving as a support therefor. Other prior art gimbalstructures have also proven unsatisfactory.

Accordingly, one object of this invention is to provide a highly rigidgimbal mounting resistant to deflection and bending of its componentparts.

Another object is the provision of a gimbal system of the immediatelyforegoing type which is especially adapted for supporting a flightsimulation table.

Yet another aim of the invention is to afford a gimbal support systemwhich'is rugged, easily constructed, inexpensive and is reliable inoperation.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawings wherein:

Fig. 1 is an isometric view of a device according to the invention, withcertain parts shown in section;

Fig. 2 is a plan view of the device of Fig. 1; and

Fig. 3 is a vertical section taken along line 33 of Fig. 2.

The gimbal mounting of the invention comprises briefly one or morecylindrically shaped supports of high rigidity in compression and inbending in all directions. Such supports are positioned on guide memberslocated on a base, and are adapted to be rotated on these guide membersby means of a centrally positioned power shaft rigidly connected to saidsupports. The reacting means or table of the device is rotatablysupported within a main ring in turn connected to a main ring shaftrotatably positioned on the supports. An auxiliary ring structure isassociated with the main ring and main ring shaft for a particularpurpose hereinafter pointed out. In addition to primary bearing memberson said supports for rotatably supporting the main ring shaft, secondarybearing members are mounted on the .supports outwardly of the primarybearing members for a purpose also set out below.

In Figures 1 to 3 of the drawing is shown a preferred embodiment of ahighly rigid gimbal support system according to the invention,comprising a circular mounting table 10 concentrically positioned withina main ring 12 and mounted for rotation on oppositely aligned spindles14 fixedly attached at one end thereof to opposite sides of the outerperiphery of the table and having their other ends rotatably supportedwithin suitable apertures 16 formed in the opposite sides of thecircular periphery of said main ring. The axis of rotation of table. 10on spindles 14 is substantially in the plane of the table and passesthrough the center thereof. A main shaft 18 is fixedly connected toopposite sides of the outer periphery of main ring 12, extendingoutwardly in opposite directions from such ring and being rotatablysupported intermediate its outer ends 20 on a pair of opposed primarybearings 22 located near the top of two oppositely positioned supportmembers or sectors 24 more fully described below. Main shaft 18 ispositioned normal to the axis of spindles 14 in the plane of ring 12,and the axis of such shaft passes through the centers of table 10 andring 12.

Two semi-circular auxiliary rings 26 and 28 are connected at rightangles to each other at approximately their respective mid-portions, oneof such rings 26 being connected to and extending vertically downwardbetween opposite portions of main shaft 18 adjacent main ring 12, andthe other auxiliary ring 28 being connected to and extending verticallydownward between opposite portions of main ring 12. Rings 26 and 28 aresuitably connected, as by welding, at their intersection 30. These tworings serve to more efficiently transfer loads from the table 10 andmain ring 12 to main shaft 18 and the primary bearings 22, thus ineffect functioning as stiffeners to reinforce the inherently flexiblemain ring 12 which is loaded normal to its plane of curvature.

The outer ends 20 of main shaft 18 are rotatably supported by a pair ofsecondary bearings 32 each mounted on a bracket 34 outwardly of primarybearings 22, the brackets being respectively attached by suitable means,as by welding, to the outer sides of sectors 24. Shaft 18 is heldagainst axial displacement by suitable conventional means (not shown).The secondary bearings afford additional support for the main shaft 18,and, the extension of such shaft to points beyond the primary bearingsprovides a continuous beam resting on four supports, including thesecondary as well as the primary bearings, thus reducing deflection ofthe main shaft under table loads to a minimum. Also, the main shaftextensions and the associated secondary bearings have additionalfunctions pointed out below.

Support sectors 24 which rotatably support main shaft 18 arecylindrically shaped and are each mounted at their base On a platform 35for rotation by means of rollers 36 on guide members or tracks 38circularly positioned on a base plate 40. The vertically positionedsupport sectors are each constructed of a pair of spaced apartcylindrically shaped plates 42 held together by a number of verticallyspaced horizontal stiffening or channel members 44 and a number ofspaced apart vertical stilfeners 45 of a type similar to members 44,such stiffeners being connected to adjacent plates 42 by any suitablemeans 3 such as by welding, by riveting, or the like. In this manner,reinforced support members 24 are provided for the loads transmittedthereto by the primary and secondary bearings 22 and 32, respectively,which support members are highly resistant to deflection and havemaximum rigidity.

Resting on horizontal platform 35 and connected perpendicularly to eachother at their mid-portions is a pair of elongated members 46 and 47having vertically positioned web or bracing elements 50 and 51 thereon,respectively, to increase the rigidity of such members. Member 46 isconnected at its opposite ends to each of support sectors 24. Elongatedcross members 46 and 47 lend further stiffness to the assembly and tosupport sectors 24. To prevent possible inclination or tipping ofvertical support sectors 24 during operation of the device and to giveadditional support to these sectors, a pair of braces 52 are connectedby suitable means between the intersecting portion of members 46 and 47,and each of the support sectors, the braces extending upwardly at anangle from such members to the inner sides of the support sectorsintermediate their ends. Integrally connected to platform 35 is arotatable power shaft 48 axially positioned between the support sectorsand extending downwardly through a bearing 49 in base plate 40, suchshaft being connected to a suitable drive means such as an electricmotor.

Mounting table 10 may be employed for mounting any type of instrument,structure or component for testing its reaction to movement about threeaxes. Support sectors 24 can be rotated at various speeds, and duringoperation of the invention device, inertia and gyroscopic loads on themounting table are transmitted by main ring 12, auxiliary rings 28 and26, and main shaft 18 to primary bearings 22. The auxiliary ringstransfer loads from table 10 and ring 12 to shaft 18 chiefly in tension,a more efficient mode of load transfer than that which takes place inthe absence of such auxiliary rings. The extension of main shaft 18beyond primary bearings 22 and the utilization of secondary bearings 32connected through brackets 34 to support sectors 24, for supporting suchextensions enables the support sectors through brackets 34 to supply adownward moment to the shaft extensions at the secondary bearings inopposition to the downward moment about the primary bearings supplied bythe load on the table, thus further aiding in reducing deflection inmain shaft 18 of the invention device and in furnishing a more positivemeans of aligning the table assembly than in prior art devices. Loadsfrom the primary and secondary bearings are transmitted to supportsectors 24, and from these members are carried to the base plate 40through rollers 36 and tracks 38.

If desired, mounting table 10 may be of a shape other than circular, andrings 12, 26 and 28 can likewise have a different configuration from thecircular shape of the embodiment shown and described above, e. g. anelliptical curvature. In place of the support sectors 24, a unitarytubular structure can be employed. The component parts of the inventiondevice are preferably of metallic construction such as steel.

From the foregoing, it is seen that the invention provides a gimbalsystem especially adapted for use as a flight simulation table, andwhich is constructed in a manner affording maximum rigidity and minimumdeflection of its component parts. The invention device is rugged, canbe readily constructed from commercially available materials, isinexpensive and is reliable in operation.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

I claim:

1. A gimbal mounting which comprises a reacting 4 means supported forfree movement about any of three mutually perpendicular axes, main ringmeans rotatably supporting said reacting means, auxiliary ring meansassociated with said main ring means, shaft means mounting said mainring means and said auxiliary ring means for rotation thereof, a basemember, guide means positioned on said base member, support meansmounted for rotation on said guide means, primary bearing means on saidsupport means rotatably supporting said shaft means, and secondarybearing means mounted outwardly of said primary bearing means onbrackets connected to said support means at a point horizontally belowsaid primary bearing means to provide additional support for said shaftmeans and to reduce any deflection thereof.

2. A gimbal mounting which comprises a reacting means supported for freemovement about any of three mutually perpendicular axes, main ring meansrotatably supporting said reacting means, auxiliary ring meansassociated with said main ring means, shaft means mounting said mainring means and said auxiliary ring means for rotation thereof, a basemember, guide means positioned on said base member, cylindrically shapedsupport means mounted for rotation on said guide means, primary bearingmeans on said support means rotatably supporting said shaft meansintermediate the ends thereof, and secondary bearing means mountedoutwardly of said primary bearing means on brackets connected to saidsupport means at a point horizontally below said primary bearing meansto provide additional support for said shaft means near the ends thereofand to reduce any deflection of said shaft means.

3. A gimbal system as defined in claim 2, including a second shaft meansconnected to said support means for rotation thereof.

4. A gimbal mounting which comprises a reacting means supported for freemovement about any of three mutually perpendicular axes, a main ringrotatably supporting said reacting means, a main ring shaft extendingoutwardly from opposed portions of said main ring, at least twoauxiliary rings connecting said main ring with said main ring shaft, abase member, guide means positioned on said base member, support meansmounted for rotation on said guide means, primary bearing means on saidsupport means rotatably supporting said main ring shaft, and secondarybearing means mounted outwardly of said primary bearing means onbrackets connected to said support means at a point horizontally belowsaid primary bearing means to provide additional support for said shaftmeans and to reduce any deflection thereof.

5. A gimbal mounting which comprises a reacting means supported for freemovement about any of three mutually perpendicular axes, main ring meansrotatably supporting said reacting means, auxiliary ring meansassociated with said main ring means, shaft means mounting said mainring means and said auxiliary ring means for rotation thereof, a basemember, guide means positioned on said base member, cylindrically shapedsupport sectors circularly mounted for rotation on said guide means,primary bearing means on said support sectors rotatably supporting saidshaft means and intermediate the ends thereof, and secondary bearingmeans mounted outwardly of said primary bearing means on bracketsconnected to said support sectors at a point horizontally below saidprimary bearing means to provide additional support for said shaft meansnear the ends thereof and to reduce any deflection of said shaft means.

6. A gimbal support system which comprises a reacting means supportedfor free movement about any of three mutually perpendicular axes, a mainring rotatably supporting said reacting means, a main ring shaftextending outwardly from opposed portions of said main ring, at leasttwo auxiliary rings connecting said main ring with said main ring shaftto transfer loads in tension from said reacting means to said main ringshaft, a base 5 member, guide means positioned on said base member,cylindrically shaped support members mounted for rotation. on said guidemeans, shaft means connected to said support members for rotationthereof, primary bearing members on said support members rotatablysupporting said main ring shaft normal to the axis of said supportmembers, and secondary bearing members mounted outwardly of said primarybearing members on brackets connected to said support members at a pointhorizontally below said primary bearing members to provide additionalsupport for said main ring shaft to reduce any deflection thereof.

7. A gimbal support system which comprises a reacting means supportedfor free movement about any of three mutually perpendicular axes, a mainring, said reacting means being mounted within said ring for rotation onan axis connected to opposite sides of the inner periphery of said ring,a main shaft normal to said axis extending outwardly from opposite sidesof the outer periphery of said ring for rotatably supporting same, at

least two auxiliary rings connecting said main ring with said main shaftto transfer loads in tension from said reacting means to said mainshaft, a base member, guide means positioned on said base member, acylindrically shaped support member mounted for rotation on said guidemeans, shaft means connected to said support member for rotationthereof, primary bearing members on said support member rotatablysupporting said main shaft normal to the axis of said support member,and secondary bearing members mounted outwardly of said primary bearingmembers on brackets connected to said support member at a pointhorizontally below said primary bearing members to provide additionalsupport for said main shaft to reduce any deflection thereof.

8. A gimbal support system which comprises a reacting means supportedfor free movement about any of three mutually perpendicular axes, a mainring rotatably supporting said reacting means, a main ring shaftextending outwardly from opposed portions of said main ring, at leasttwo auxiliary rings connecting said main ring with said main ring shaftto transfer loads in tension from said reacting means to said main ringshaft, a base member, a guide means positioned on said base member, aplurality of cylindrically shaped support sectors positioned normal tosaid base member and circularly mounted for rotation on said guidemeans, shaft means connected to said support sectors for rotationthereof, primary bearing members on said support sectors rotatablysupporting said main ring shaft intermediate its ends normal to the axisof said support sectors, and secondary bearing members mounted outwardlyof said primary bearing members on brackets connected to said supportsectors at a point horizontally below said primary bearing members toprovide additional support for said main ring shaft to reduce anydeflection thereof.

9. A gimbal support system which comprises a reacting means supportedfor free movement about any of three mutually perpendicular axes, a mainring rotatably supporting said reacting means, a main ring shaftextending outwardly from opposed portions of said main ring, at leasttwo auxiliary rings connecting said main ring with said main ring shaftto transfer loads in tension from said reacting means to said main ringshaft, a base member, guide means positioned on said base member, a pairof opposed cylindrically shaped support sectors positioned normal tosaid base member and circularly mounted for rotation on said guidemembers, a pair of opposed primary bearings near the top of each of saidsupport sectors rotatably supporting said main ring shaft intermediateits ends normal to the axis of said support sectors, a pair of secondarybearings each mounted on a bracket outwardly of said primary bearingsfor additionally rotatably supporting said main ring shaft near the endsthereof to reduce any deflection of said shaft, said brackets beingrespectively attached to the outer sides of said support sectors at apoint horizontally below said primary bearings and a rotatable powershaft axially positioned between said support sectors and connectedthereto for rotation thereof.

10. Ahighly rigid gimbal support system which comprises a reactingmeans, a main ring, said reacting means being mounted within said ringfor .rotation on an axis connected to opposite sides of the innerperiphery of said ring, a main shaft normal to said axis extending fromopposite sides of the outer periphery of said ring for rotatablysupporting same, a pair of semi-circular auxiliary ring members adaptedto transfer loads in tension from said reacting means to said mainshaft, said auxiliary ring members being connected at right angles toeach other, one of said ring members being connected to and extendingdownwardly between opposite portions of said main shaft and the otherbeing connected to and extending downwardly between opposite portions ofsaid main ring, a base member, guide members circularly positioned onsaid base member, a plurality of opposed cylindrically shaped supportsectors circularly mounted for rotation on said guide members, a pair ofopposed primary bearings on said support sectors rotatably supportingsaid main shaft intermediate its ends normal to the axis of said supportsectors, a pair of secondary bearings each mounted on a bracketoutwardly of said primary bearings for additionally rotatably supportingsaid main shaft near the ends thereof to reduce any deflection of saidmain shaft, said brackets being respectively attached to the outer sidesof said support sectors at a point horizontally below said primarybearings, a rotatable power shaft axially positioned between saidsupport sectors and extending through said base member, and a memberconnecting said support sectors with said power shaft for rotationthereby.

11. A highly rigid gimbal support system which comprises a mountingtable, a main circular ring, said table being mounted within said ringfor rotation on an axis in the plane of said table passing through thecenter thereof and connecting the outer periphery of said table with theinner periphery of said ring, a. main shaft normal to said axisextending from opposite sides of the outer periphery of said ring forrotatably supporting same, a pair of semi-circular auxiliary ringmembers adapted to transfer loads in tension from said mounting table tosaid main shaft, said auxiliary ring members being connected at rightangles to each other at their mid-portions, one of said ring membersbeing connected to and extending downwardly between opposite portions ofsaid main shaft and the other being connected to and extendingdownwardly between opposite portions: of said main ring, a base member,guide members circularly positioned on said base member, a plurality ofopposed cylindrically shaped support sectors positioned normal to saidbase member and circularly mounted for rotation on said guide members, aplurality of stiffening members connected to said support sectors, apair of opposed primary bearings near the top of each of said supportsectors rotatably supporting said main shaft intermediate its outer endsnormal to the axis of said support sectors, a pair of secondary bearingseach mounted on brackets outwardly of said primary bearings foradditionally rotatably supporting said main shaft near the ends thereofto reduce any deflection of said main shaft, said brackets beingrespectively attached to the outer sides of said support sectors at apoint horizontally below said primary bearings, a rotatable power shaftaxially positioned between said support sectors and extending downwardlythrough said base member, and a platform member connecting said supportsectors with said power shaft for rotation thereby.

12. A support system as defined in claim 11, including a plurality ofbraces connected to said platform and extending upwardly therefrom tosaid support sectors.

13. A support system as defined in claim 11, wherein said stiffeningmembers are composed of a plurality of References Cited in the file ofthis patent UNITED STATES PATENTS Stimpson Apr. 9, 1901 Urfer Jan. 23,1934 Braddon et al. Oct. 12, 1948 Isserstedt Dec. 6, 1949

